3pi Reference Catalogs

Some information on the reference catalogs generated from PS1. Since May 2012, we have been using a reference catalog generated based on PS1 data. This catalog provides a better photometric tie than the old 2MASS-based synthetic photometry database, and it has better relative astrometry. However, it has some holes, some non-uniform coverage, and it has absolute astrometry errors. I built a new reference database in 2014 March, and it addresses some of these issues. We are not yet using it, however, because of some astrometric glitches, with repairs underway. This pages compares the coverage of the two databases. The images below show log(density) of the objects in the reference database (log (N/deg2)) as a function of filter. The left plots show the old (2012.05.24) reference catalog, while the right plots show the new (2014.03.31) reference.

Note the spotty coverage of the 2012.05.24 database, and especially the handful of green blocks where entire regions are missing.